Just replacing my in tank fuel pump and the main wiring looks like this:

Click image to enlarge

Click image to enlarge

So the plug to the fuel system has all the right wires and matches with the wiring diagram of whatever year it happens to be.

Then I have this fudged connected with a black wire & brown/blue wire on one side and a green/blue wire & orange/blue wire on the other side.

I've no idea if they are supposed to fit together but they both seem to be coming from the same main loom that goes to the fuel pump and the RHS rear seat.

The loom at that point has been unwrapped by a previous bodger so I'm unsure how or why these wires come all the way to this point if they are supposed to fit together.

Click image to enlarge

Click image to enlarge

What comes to my mind is, someone needed to do that hack to get things to work properly (hopefully it was working properly?)

If that's the case, I'd be tempted to just clean things up a bit and leave it as is.

If it works, don't with it to make it stop working

Sadly the whole point of this farce has been to try to work out why the car won't start.

The secondary fuel pump under the bonnet can be heard, although unclear if it actually works. The in-tank fuel pump cannot be heard at all, hence the need to replace it.

However, random connectors and botched electrical tape on wiring looms sets the alarm bells off.

I suspect the red connector might be for cars with heated rear seats, but the wires leading to the grey connector are definitely connected to the top of the fuel pump cover and I cannot find the connector, etc. on any wiring diagram or photo so I was hoping someone else might recognise it.

I just want the stupid car to start as the previous owner claimed it was working and just needed a fuel pump, so I'm trying to see whether there was something more fundamental going on relating to the purpose of this grey connector.